The promulgation of optical networks has been integral to the advancement of information technology. From local-, wide-, and metro-area networks to cable television networks, optical networks have brought increased services and information access to consumers. Optical networks offer the high-bandwidth needed for high-volume usage and data intensive content, such has high quality video and audio.
These optical networks commonly rely upon an optical fiber backbone, with optical repeaters, amplifiers and transceivers coupled across the backbone to send and receive optical signals. Switches and routers, for example, use transceivers to control data dissemination and collection in various network environments, such as an Ethernet-based networks and larger Internet Service Provider (ISP) networks. Host bus adaptors (HBA), redundant-array-of-independent-disks (RAID) modules, Fibre Channel devices and other technologies use optical networks in computing environments to connect storage systems and processors for high-bandwidth high-interconnectivity communication between computer systems.
As networks become more diverse in type and more complex in operation, more optical components are needed. Network designers are often called upon to build complex systems using equipment from many different vendors. Yet, while the availability of competing products may be useful this availability has led to a lack of device uniformity. A network designer is cautious when selecting an optical module, because modules may or may not accurately fit the network device's mounting cage, depending on the relative dimensions of the two.
Some vendors have implemented standards for optical transceivers to help reduce variability issues. For example, a manufacturer may design small form-factor pluggable transceivers (SFPs) compatible with standards from the Small Form Factor Pluggable (SFP) Multi-Source Agreement (MSA) standard (SFP/MSA). This standard may be used for optical systems such as asynchronous transfer mode (ATM), fiber-distributed data interface (FDDI), Fibre Channel, Fast Ethernet and Gigabit Ethernet, and Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH) applications. The MSA agreements cover package dimension, connector system design, host board layout, and electrical interfaces, among other things. The agreements evidence guidelines, however.
Even with the SFP/MSA, there is still variability among network device manufacturers. As a result, transceiver manufactures still run the risk of producing equipment incompatible with a particular network device. Yet, proper optical module engagement may be important to longevity. Improperly fitting modules also run the risk of alienating network administrators and designers, who are reluctant to reuse optical modules that do not form a ‘good’ fit in previously-installed devices. The various latching tolerances on present and past cage designs has been particularly problematic for optical transceivers, as customers typically want an optical module they can easily insert and remove.
Some latching mechanisms have been proposed for optical devices, but the designs are problematic in that they do not form tight seals and can degrade in performance or completely malfunction over time. For example, designs often rely upon movable parts that do not have sufficient engagement or which can break under normal operation forces by their use of inferior construction materials or inferior locking configurations.